No increased risk of flare in ulcerative colitis patients in corticosteroid-free remission after stopping 5-aminosalicylic acid: A territory-wide population-based study

Background and aim: Whether 5-aminosalicylic acid (ASA) can be stopped in patients with stable ulcerative colitis (UC) remains unclear. We aimed to examine whether 5-ASA can be safely withdrawn in UC patients who have been in corticosteroid-free clinical remission for ≥ 1 year.

Methods: This is a retrospective cohort study using territory-wide healthcare database in Hong Kong. Primary outcome was development of UC flare, defined as new corticosteroid use or UC-related hospitalizations within 5 years. UC patients on oral 5-ASA ≥ 2 g daily for ≥ 1 year with C-reactive protein (CRP) < 10 mg/dL and no 5-ASA dosage escalation, UC-related hospitalization or corticosteroid use in the past year were included. Patients on biological agents were excluded. Patients were classified as "stopping" if 5-ASA was withdrawn for ≥ 90 days within follow-up period. We performed multivariable Cox regression models adjusting for demographics, blood parameters and immunosuppressants used. Adjusted hazard ratio (aHR) with 95% confidence interval (CI) was reported comparing stopping and continuous-use groups.

Results: A total of 1408 patients were included with a median follow-up duration of 41.8 months (interquartile range [IQR]: 17.2-60.0 months). Stopping 5-ASA was not associated with an increased risk of UC flare (aHR 0.91; 95% CI 0.64-1.31; P = 0.620). A higher CRP levels at the time of stopping 5-ASA (aHR 1.15; 95% CI: 1.01-1.30; P = 0.037) were associated with increased risk of flare.

Conclusion: Stopping 5-ASA in UC patients in corticosteroid-free remission for ≥ 1 year was not associated with increased risk of flare. Future prospective trials should evaluate the role of stopping 5-ASA in stable UC patients.